Dry-chemical fire-extinguisher



.C. S. DAVIDSON. DRY CHEMICAL FIRE EXTINGUISHER. APPLICATION FILED JULY 2. I919.

' 1,354,093. atentedSept. 28,1920.

' I zeg INVENTO'R. I W W UNITED STATES PATENT OFFICE.

CHARLES S. DAVIDSON,- OF LOS ANGELES, CALIFORNIA, ASSIGNOR OF ONE-THIRD T0 FRANK M. POOL AND ONE-THIRD T0 JOHN FORNIA.

E. FABER, BOTH OF LOS ANGELES, CALI- DRY-CHEMICAL FIRE-EXTINGUISHER.

Specification of Letters Patent.

Patented Sept. 28, 1920.

Application filed July 2, 1919. Serial No. 308,216.

To all 1072 am it may concern Be it known that I, CHARLES S. DAVIDSON, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Dry-Chemical F ire-Extinguisher, of which the following is a specifi cation.

This invention relates to fire extinguishers and especially to that type constructed and adapted to spray a dry chemical mixture of powders upon the flames to extinguish them.

An object of the invention in general is to make provision for extinguishing flames with a combination or mixture of chemicals in owder form.

nother object of the invention is to produce an apparatus of this character of comparatively simple construction and one that is reliable in operation.

Another object is to construct an apparatus of this character which can be conveniently carried on the back of the operator, or otherwise as desired.

The accompanying drawings illustrate the invention:

Figure 1 is a vertical mid section of a fire extinguisher built in accordance with the provisions of this invention, a mixture of powdered chemicals being shown in the con tainer.

Fig. 2 is a plan section on line indicated by m m Fig. 1.

There is provided a container or reservoir 1 of suitable shape and of substantially air tight construction. The ends 2, 2 of the container are provided with bearings 3 to journal a shaft 4 which is provided with stirring blades 5, there being any required number of said stirring blades. The bottom end 2 of the container is provided with a stufling box 6 to minimize leakage around the shaft 4:. The shaft 4 is provided with a crank 7 whereby the shaft may be turned to rotate the blades so as to stir and mix the powdered chemicals placed in the lower portion of the container 1, said chemicals being indicated by the character 8.

The upper end 2 of the container is provided with an opening 9 into which is screwthreaded the nipple 10 of a pressure gage 11. The pressure gage 11 may be removed when it is desired to charge the container with the chemicals. The upper end 2 of the minat ing adjacent the upper end 2 of said container. Connected to the tube 15 by a coupling 17 is a hose 18 provided with a nozzle 19.

In practice, to put the apparatus in condition for use, the pressure gage 11 will be removed and the lower portion of the container will be charged through the opening 9 with dry chemicals in powdered form and of such character that they are capableof extinguishing flames. Such dry chemicals are well known in the art pertaining to chemical fire extinguishers and therefore a detailed description herein of the chemicals is unnecessary. After the chemicals have been introduced to the container, the hose coupling 12 will be connected with a suitable source of compressed air supply and the upper portion of the container or space above the chemical charge will be charged with compressed air. The air pressure em ployed may be forty pounds per square inch more or less.

After, or before, the container has been charged with the chemicals and compressed air, the chemicals will be thoroughly mixed by turning the crank 7. The apparatus is now ready for use and to extinguish a fire the operator will open the valve 14, whereupon the chemical mixture will be forced by the compressed air through-the tube 15 and hose 18 and the chemical mixture will issue from the nozzle 19 in the form of a dry spray. The operator will direct the dry chemical spray upon the fire until it is extinguished. For convenience in using, the operator may strap the container onto his back. It is understood that the container 1 will be maintained in more or less upright position so that the chemical mixture will be in the lower portion of the container adjacent the port 13, in order that the air pressure will be available behind the chemicals tainer through the port 13.

for forcing said chemicals out of the con- I am aware that liquid chemicals have heretofore been employed in fire extinguishing apparatus and that the chemicals are'oi such nature that when they are brought together by inverting of the container the Which the apparatus may be prepared for use and maintained at maximum efiiciency.

The dry chemicals in the container 1 will not deteriorate and they may be thoroughly mixed at suitable intervals and prevented from caking or cakes already formed may be broken up by a few turns of the crank 7. The pressure gage 11 constantly indicates the amount of air pressure and if said air pressure is reduced below a certain value by reason of an sli 'ht le'aka e of air from the container or by reason of using the apparatus, the hose coupling 12 will be connect'ed-w'i-th the compresse'dair supply and the pressure will be brought up to a desirable maximum.

It is understood that the invention is not limited to the exact details of construction shown in the drawings and described above, but that the invention also includes such changes and modifications as lie within the spirit and scope of the appended claim.

I claim:

In a dry chemical fire extinguisher, a container in the form of a cylinder having a port adjacent its lower end, a valve for said port, a tube connected with the valve and extending to the upper end of the container, a hose fastened to the upper end of the tube, hearings in the opposite ends of the container, a shaft extending from end to end of the container and journaled in said bearings and having one end projecting outside of the container, a crank on the projecting end of the shaft, and stirring blades on the shaft extending at right angles thereto inside of the container.

Signed at Los Angeles, California, this 25th day of June 1919.

CHARLES S. DAVIDSON.

lVitnesses j Gnonen H. Hires, L. BELLE l/Vnnvnn. 

